Single Slit Diffraction

Concept: Physics (Optics) - Intensity in Single Slit Diffraction.

Step 1: Understand the factors affecting principal maximum intensity. In a single-slit diffraction pattern, the intensity of the central (principal) maximum depends on the amplitude of the incident wave and the coherent addition of wavelets from the slit.

Step 2: Analyze the effect of slit width. While changing the slit width significantly alters the width of the diffraction pattern (wider slits result in narrower patterns), it does not change the maximum intensity of the principal peak itself.

Step 3: Conclusion. Since the intensity of the principal maximum is independent of the slit width, doubling the width leaves the intensity unchanged. $ $

Concept: Physics (Optics) - Single-Slit Diffraction.

Step 1: Analyze the intensity distribution. In single-slit diffraction, the central maximum is the brightest. As the order of the fringes ( ) increases, the intensity of the subsequent maxima decreases significantly. Therefore, the fringes are of unequal intensity.

Step 2: Analyze the fringe width. The position of the minima is given by . The central maximum is twice as wide as the secondary maxima. Furthermore, because the sine function is non-linear, the angular separation between higher-order minima changes. Therefore, the fringes are of unequal width.

Step 3: Conclusion. Both the width and the intensity of the fringes vary across the diffraction pattern. The central maximum is the widest and brightest, with fringes becoming narrower and dimmer moving away from the center. $ $